Mamlaka hii ni muhimu.

• mamlaka = authority, power, or sometimes an authority/body, depending on context
• hii = this
• ni = is
• muhimu = important

So the structure is basically:

mamlaka hii = this authority
ni muhimu = is important

Because Swahili usually puts demonstratives like this and that after the noun, not before it.

So:

• mamlaka hii = this authority
• not hii mamlaka in normal neutral word order

This is a very common difference from English. Compare:

• kitabu hiki = this book
• mtu huyu = this person
• mamlaka hii = this authority

Swahili demonstratives have to agree with the noun class of the noun. In this sentence, mamlaka is being treated as a singular noun of the class that takes hii.

That means:

• mamlaka hii = this authority

If the noun belonged to a different class, this would look different. For example:

• mtu huyu = this person
• kitabu hiki = this book
• mji huu = this town

So hii is not random; it matches mamlaka.

Here it is singular, because the demonstrative hii shows singular agreement.

A useful thing to know is that some Swahili nouns can have the same basic form in both singular and plural, and the agreement words show the difference. So you may see:

• mamlaka hii = this authority
• mamlaka hizi = these authorities

So even though mamlaka itself does not change here, the agreement word tells you the number.

ni is the copula here — the word that links the subject and the description, like English is.

So:

• Mamlaka hii = the subject
• ni muhimu = what is being said about it

Together:

• Mamlaka hii ni muhimu = This authority is important

In sentences like this, ni is very common and works like a simple present-tense to be.

Because muhimu is one of the adjectives that usually stays the same form. Not every Swahili adjective changes with noun class.

Some adjectives do agree:

• mtu mkubwa = big person
• kitabu kikubwa = big book

But muhimu is normally invariable:

• mtu muhimu = an important person
• kitabu muhimu = an important book
• mamlaka muhimu = an important authority

So in Mamlaka hii ni muhimu, muhimu stays the same.

No, Swahili does not have articles that work like English a/an/the.

Whether something is definite or indefinite usually comes from context or from words like demonstratives. In this sentence, hii already makes it specific:

• mamlaka hii = this authority

That is naturally definite, so there is no separate word for the.

Yes. Depending on context, mamlaka can refer to:

• authority in a general sense
• power
• jurisdiction
• the authorities
• a governing body, agency, or administration

So although the grammar of the sentence stays the same, the most natural English translation may change depending on the situation.

A simple approximate pronunciation is:

• mamlaka → mahm-LAH-kah
• hii → HEE-ee
• ni → nee
• muhimu → moo-HEE-moo

A few helpful pronunciation points:

• Swahili words are usually pronounced clearly syllable by syllable.
• Stress is normally on the second-to-last syllable.
• hii has two vowels pronounced separately, not as a single English hee.

So the whole sentence sounds roughly like:

mahm-LAH-kah HEE-ee nee moo-HEE-moo

It would still begin with the noun, and the demonstrative would normally come later:

• mamlaka muhimu hii = this important authority

A good rule of thumb is that Swahili usually puts the noun first, then descriptive words, and the demonstrative often comes near the end of the noun phrase.

So compare:

• mamlaka hii ni muhimu = this authority is important
• mamlaka muhimu hii = this important authority

The first is a full sentence. The second is just a noun phrase.